Question

A 2.80kg mass is dropped from a height of 4.50m. Find the PE and KE when it is 3.00m above the ground.

Answer 1

Initial PE = 2.8 * 10 * 4.5

Answer 2

PE at 3m height = 2.8 * 10 * 4.5
KE at 3m height = Change in PE
= 2.8*10(4.5-3)

Answer 3

@_loree22

Answer 4

My PE is correct but my KE isn't. I got 42 but when I plug the number in, its mark as wrong.

Answer 5

@vikrantg4

Answer 6

PE at 3 m height = 2.8 * 10 * 3 = 84 , Sorry My bad
KE is 42 !

Answer 7

Thank you :) @vikrantg4

Answer 8

Anytime !

Answer 9

Can you help me find the height for this problem.
A 0.155kg arrow is shot upward at 31.4m/s. what is its PE.

Answer 10

calculate the kinetic energy first.. the same energy will become PE at max height

Answer 11

I did, I got 76.4119. When I plugged the number in I got 116.0696761.

Answer 12

Put it keeps saying I got it wrong, what did I do wrong ?

Answer 13

What is KE from one of these values ?

Answer 14

My KE is 76.411 and for PE I got 116.0696761.

Answer 15

No No.. The KE is 76.411
This must be the PE at max height according to conservation of mechanical energy.
So PE = mgh = 76.411
h = 76.411/ (9.8 * 0.155)
= 50.3 m

Answer 16

Thank you :)